SURROUNDED by divers in skin-tight Speedos, ­acrobats on swings and delirious fans, the Duchess of Cambridge had plenty to keep her entertained.

SURROUNDED by divers in skin-tight Speedos, ­acrobats on swings and delirious fans, the Duchess of Cambridge had plenty to keep her entertained.

But as the extravagant antics carried on around her at a lavish charity party, Kate’s thoughts were well and truly on new husband Prince William.

The 29-year-old told guests she was having a fantastic time as a new royal since the couple’s wedding in April.

One revealed: “Kate said she was ‘loving it’ when asked what married life was like. She added that it was surreal sometimes but that’s to be expected.

“She said she was totally and blissfully happy and her eyes lit up whenever William’s name was mentioned. The pair are clearly so in love.”

Kate and William’s first public engagement as a couple was as guests of honour at the Ark 10th ­anniversary party to raise funds for deprived kids at Princess Diana’s former home Kensington Palace. And the Mirror was there to witness it.

But it was certainly not quite the serene affair normally associated with royal events.

Guests paid up to £100,000 to be at the party. Boozy super-rich bankers, ­hedge-fund managers and property developers were among the crowd and they surged forward at every ­opportunity to get a glimpse of Kate.

Wills was even wolf-whistled by female bankers as the expensive drink flowed. And vast amounts of cash was splashed at a charity auction with lots worth a combined £17.2million.

The extraordinary scenes left Kate and Wills a little shell-shocked when they arrived for the do on Thursday night, organised by Ark founder Arpad Busson. As Kate walked up the purple carpet, she spotted the Speedo-clad troupe of men and women who were acrobatically diving into a massive swimming pool to entertain guests.

She pointed at one man and was overheard declaring in astonishment: “Look at that, Will.” Her 28-year-old husband collapsed in fits of hysterics. Organisers had also built huge swings above the tables where acrobats performed a number of stunts just yards above the royal couple’s heads – like a scene from Moulin Rouge.

A guest said: “It was the most ­extravagant, ostentatious, over-the-top bash you can ever imagine with bankers splashing their cash like there’s no tomorrow. It was not the sort of occasion you would normally associate with royalty. But Kate and Wills took it in their stride like true professionals.”

The duchess wore a £3,835 rose pink sequinned Jenny Packham dress for the party, where tickets cost a minimum £10,000.

After taking in the action for 45 minutes, the couple split and started mingling among the guests, who included Kevin Spacey, David Furnish, Jamie Cullum and Liz Hurley. And Kate was soon working the crowd like she had been doing it all her life.

She even put Liz in the shade, and she is no stranger to attracting the attention of fans with her revealing dresses.

As Wills chatted to Busson, who has an on-off relationship with Uma Thurman, a guest asked Kate: “Where’s your husband?” Jokily rolling her eyes as if she knew the question was ­inevitable, she replied: “We always get split up at these things.”

As the night wore on and the drink was guzzled, the couple had to contend with an increasingly over-familiar crowd. The mega-rich bankers fell over ­themselves to get mobile phone pictures of the newly-weds.

One onlooker said: “It was behaviour more akin to a pop concert than a high profile royal engagement.”

After dinner, the wealthy crowd started bidding for luxury items in an auction with special buzzers at their tables. Over-the-top prizes included a “bespoke luxury tree house”. It went for £140,000. One table bid £450,000 to take nine friends on a private jet to Monte Carlo where they would race the world’s largest sailing yacht – The Maltese Falcon – in the Perini Cup.

Another lot promised fashion dressing and dinner: “An afternoon with the renowned designer Tom Ford.” One guest paid £165,000 for the prize, to loud gasps from the audience.

Cardboard packaging used for a diarrhoea medicine – signed by Wills, Kate, rockers the Kings of Leon and David Cameron - went for £120,000. Ark chairman Ian Wace held up the packet and admitted it was worth “f*** all”.

Other lots included lunch with US Vogue editor Anna Wintour (£180,000) and a ticket to movie mogul Harvey Weinsten’s Oscar Party at Soho House (£250,000).

Dressed in a black dinner suit and bow tie, Wills stood up to make a speech, and looked a little bemused to be greeted with a chorus of loudwolf-whistles by a number of women.

He told the audience: “I’m not quite sure I am deserving of that intro.

“I would like to share with you the conversation I am going to have with my grandmother tomorrow as I try and describe this: the swimming pool and the men wearing the most tight Speedos I have ever seen in my life.”

As he returned to the table he shared with Jemima Khan, Laura Bailey and Mariella Fostrup, the whistles started again. Wills and Kate left at 10.45pm as Mark Ronson took to the stage for a DJ set. Kings of Leon then performed a blistering 45 minute gig at midnight.

A source close to the band said: “It’s fair to say it wasn’t their usual crowd of indie-kids drinking beer from plastic pints. Instead they were faced with a sea of black tied bankers all dancing rather badly while swigging from champagne flutes.